Controller for electric locomotives



(No Model.) 14 Sheets-Sheet 1.

J. .W. DARLEY, J1. CONTROLLER FOR ELECTRIC LOGOMOTIVES-.

No. 530,507. Patented Dec. 11.1894.

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(No Model.) O 14 Sheets-Sheet 2.

J. W. DARLEY, J1.

CONTROLLER FOR ELECTRIC LOCOMOTIVES.

No. 530,507. Patented Dec. 11, 1894,

WIT E5555- N H K 14 Sh'eetsSheet 3.

(N0 ModeL) J. W. DARLEY, Jr. CONTROLLER FOR ELECTRIC LOCOMOTIVES. NO.530,507.

Patented Dec 11,1894,

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(No Model.) 14 Sheets-Sheet 4.

J. W. DARLEY, Jr. CONTROLLER FOR ELECTRIC LOCOMOTIVES. No. 530,507.

Patented De 11, 1894.

14 Sh,eetsSheet 6,

(No Model.)

J. W. DARLEY? J1 GONTRGLLER FOR, ELECTRIC LGGOMOTIVES. No. 530,507.Patemefi Dec. 11, 1894.

(No Model.) 14 Sheets-Sheet 7. J. W. DARLEY, Jr.

OONTROLLER FOR ELECTRIC LOCOMOTIVES. No. 530,507. Patented Dec. 11,1894.

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Patented Dec. 11

WnplESarza- (No Model.)

CONTROLLER FOR ELECTRIC LOCOMOTIVES.

14 Sheets-Sheet 9.

No. 530,507. Patented Dec. 11,1894.

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J. W. DARLEY, Jr. CONTROLLER EOE ELECTRIC LOCOMOTIVES.

Patented Dec. 11,1894.

\M ple-sazs $5.7M.

(No Model.) 7 14 Sheets-Sheet 11.

- J. W. DARLEY, Jr. CONTROLLER FOR ELECTRIC LOCOMOTIVES.

Patented Dec. 11,1894.

(No Model.) 14 Sheets-Sheet 12. J. W. DARLEY, Jr.

CONTROLLER FOR ELECTRIC LOCOMOTIVES. .No. 530,507. Patented Dec. 11,1894.

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J. W. DARLEY, Jr. CONTROLLER FOR ELECTRIC LOCOMOTIVES.

No 530,507. Patented Dec. 11, 1894.

QKFMW- o.4 U, 11 M (No Model) 14Sheets-Sheet 14.

J. W. DARLEY, Jr.

CONTROLLER FOR ELECTRIC LOCOMOTIVES. NO. 530,507. Patented DOC. 11,1894.

UNITED STATES PATENT OFFICE.

JOIIN IV. DARLEY, JR, OF BALTIMORE, MARYLAND, ASSIGNOR TO THE GENERALELECTRIC COMPANY, OF BOSTON, MASSACHUSETTS.

CONTROLLER FOR ELECTRIC LOCOMOTIVES.

SPECIFICATION forming part of Letters P atent No. 530,507, datedDecember 11, 1894.

Application filed November 16, 1893. Serial No. 491,145. (No model.)

To all whom it may concern.-

Be it known that LJOHN W. DARLEY, Jr., a citizen of the United States,residing at Baltimore, State of Maryland, have invented a certain newand useful Improvement in Controllers for Electric Locomotives, of whichthe following is a specification.

My invention relates to the control of the motors of electriclocomotives and particularly to the requirements of apparatus employedin heavy traffic, necessitating the use of a number of motors upon eachlocomotive; and has for its object to construct a compact apparatusoperated preferably, though not necessarily, by power, (as for example,by compressed air,) controlling the speed and the power by theseries-parallel system, as it is commonly called. In this system asdeveloped in the mechanism herein described and illustrated, the motorsare combined, either with or without a resistance, though it is usuallyemployed, in various combinations in series or parallel, to give variousspeeds and torques; and my invention resides in the mechanical andelectrical means I employ to effect these combinations readily, rapidly,and safely.

It further resides in the improved meansI adopt of breaking the circuitupon an excess of current without damage to the controller, and incertain interlocking devices, whereby it becomes practically impossibleto operate the apparatus except in the manner in which it is designed tobe used; and lastly, in many details contributing to the efficiency andease of operation and repair of the controller, all of which will bemore fully described hereinafter, and the novelty of which will bedefinitely pointed out in the claims.

To attain the ends pointed out, I providea vertical frame, in which Imount four horizontal cylinders, provided with contacts adapted to makeconnection with stationary brushes, by the revolution of which cylindersthe path and eifect of the current are changed, as hereinafter pointedout. The main or commutating cylinder serving to alter the relation ofthe motors, is preferably revolved in either direction at will by power.This cylinder has four running positions in which positions only it maybe brought to a astand. Geared to it so as to make five revolutions foreach turn of the commutating cylinder is a resistance-cylinder, by whichthe amount of resistance in circuit may be varied in the first runningposition. By five revolutions I do not mean five complete turns, butfour complete turns and a nearly complete fifth turn, upon which theresistance cylinder advances to the last position or itsshort-circuiting position. Should it move a full turn on its fifthrevolution, the circuit would be opened, as will be better understoodhereinafter. The commutating cylinder does not make a completerevolution, but such part of a revolution as it does make is sufficientto turn the resistance cylinder through the four complete turns and thefifth partial turn, as just explained. Below the commutating cylinderand having motion independent of it, I arrange a cut-out cylinder,operated by hand; and below this cut-out cylinderI place a reversingcylinder having motion independent of the cut-out cylinder and onlyconnected to the com mutating cylinder by interlocking mechanismdesigned to prevent the reversal of the motors except when they are soconnected as to make it safe to reverse them. I thus combine in a singlecompact piece of apparatus taking but little room in the cab all themechanism needed to control the motors of a large locomotive.

In the embodiment of my invention herein illustrated I have shown itapplied to a locomotive having six motors; but it may be equally wellemployed with eight or more, or with a less number. Many variations mayalso be made from the precise arrangements shown, without departing fromthe spirit of my invention; all of which I aim to embrace by my claims.

In the accompanying drawings hereby re ferred to and made part of thisspecification, Figure l is a side elevation; Fig. 2, an enlarged sideview of the commutating and resistance cylinder-gearing, thecircuit-breaker hereinafter described and the commutating and resistancecylinders being removed to show the construction,and the air-enginebeing shown in dotted lines and its valve-gear in section. Fig. 3 is anenlarged side elevation; Fig. 4, a front elevation, and Fig. 5 a

sectional detail upon the line 55, of Fig. 4., of the circuit-breaker Iemploy. Fig. 6 is a detail of a stop employed for the commutatingcylinder. Fig. 7 is a sectional View of the air-engine, taken on theline 77 of Fig. 2, the valve being omitted. Fig. 8 is a side elevationand Fig. 9 an end elevation of the resistance cylinder, showing theblow-out magnets therein; Fig. 9", a detail of one of these blow-outmagnets. Fig. 10 is an enlarged rear elevation showing the brushes uponthe resistance and commutating cylinders and one set of brushesrespectively upon the cut-out and reversing cylinders. Fig. 11 is a viewshowing the contacts and cross connections of all the cylinders,developed in plane. Figs. 1 to 9 are diagrams of the motor connectionscorresponding to the positions l to 9 of the commutating cylinder. Fig.12 shows the motor designations which I adopt. Fig. 13 shows the cut-outcylinder with the motor a cut out, the commutatingcylinder being in itsfirst position. Fig. let shows the cut-out cylinder in the sameposition, the commutating cylinder being in its first multiple position,and Fig. shows the cut-out cylinder still in the same position, whilethe commutating cylinder is in its first running position in multiple;in the last three views only the operative contacts being illustrated.Figs. 13, 14, and 15 show diagrammatically the connections in theposition shown in Figs. 13, 14:, and 15. Figs. 16, 17, and 18 are sideand end elevations respectively of the stands and operating handles bywhich the movements of the apparatus are controlled. Fig. 19 is adetail. Figs. 20 to 25, inclusive, show the various combinations ofmotors when the cut out cylinder is in positions adapted to cut out oneof the motors.

Like letters and figures denote like parts in all the views.

In Fig. 1, A is a vertical frame, secured at top and bottom by the bolts13, B, to the framing of the cab or other suitable support securedthereto. 0' is the resistance cylinder, shown best in Figs. 8 and 9,described hereinafter. 0 is the commutating cylinder, actuated by arotary air engine, as shown in Figs. 2 and 7. O is the cut-out cylinder,operated by hand through the gear 1 the worm 1 and the handle I. C isthe reversing cylinder, having only two positions, as indicated by thenotches G, G serving as stops for the bent lever G and operated by therotating arm or lever G, which in turn is actuated by the rod G which ispreferably attached to a treadleoroperatinglever. Notshown. D,D, &c.,are the stranded cables serving to convey the current, which are oflarge size and adapted to carry any possible current which may be usedin the system.

The parts of the circuit-breaker are shown in their proper position onthe controller, K being a pole-piece of the blow-out magnet; K, thechimney or box into which the arc is blown; L, L If, L the magneticcircuit of the apparatus, all more fully described in connection withthe detail views in Figs. 3 and 4.

Referring to Fig. 2, the interacting devices by which I secure only amotion of the resistance cylinder appropriate to the position of thecommutating cylinder are illustrated, in connection with the air-engine.U is a rod, actuated by a suitable handle (not shown) andoperatingalever U, rocking upon a stud, U attached to the frame A. Ashort offset arm U carrying a friction roller, U, projects from thelever U, and engages with notches or cut-away portions Z Z Z Z of araised flange or rim Z upon the commutating cylinder 0 It will beobserved that when the roller U engages with either of the notches Z&c., it allows the cylinder 0 to be brought to a stand. This cylinder isgeared to O by the gears X, X, and hence in these positions the cylinder0 is also brought to a stand. Then the roller engages \vith the notch orcut-away part Z however, as shown in the drawings, the rotation of thecylinder C isnot stopped thereby, and as this notch comprisesapproximately one-fifth of the circumference, the cylinder 0 may becompletely revolved, thus interposing any desired amount of resistancewithin the capacity of the rheostat employed. The cylinder isillustrated in the off position.

It is necessary that the resistance cylinder should have a series ofdefinite contact-positions (to prevent partial contacts and avoidarcing) in which only it may stop. To attain this object, the lever Ucarries upon its en d at U a rod U, which at its upper end is connectedto a toggle U operating to adgance and retract the stop U which engagesat de terminate points with the notches \V, \V, &c., arresting thecylinder C at proper points where its contacts are fully made. As willbe readily observed, the stoppages of the cylinder 0 also arrests thecylinder 0 so that the roller U on the arm U will only move in the notchZ until such time as the detent or stop U enters one or another of thenotches W. The two cylinders are thus perfectly interlocked in suchmanner that it is impossible for either of them to move except as may beintended or to stop except at a running position.

It is to be understood that the resistance can only be varied in thefirst running positions of the commutating cylinder. Inmakingtheothercombinations the resistanceis not capable of beingchanged, although suitable notches might be provided in the flange Z(which acts as an index for the commutating cylinder), permitting avariation of resistance in other positions of that cylinder. By this Imean, not that the resistance is cutout or in toto, but that there is norunning position after the first in which the resistance is in circuit.

In dotted lines in Fig. 2, is shown the airengine operating thecommutating cylinder,

its valve being shown in section; Fig. 7 being IZC also referred to. Yis the piston, the engine being of the rotary type, and Y the fixedabutment, made in one piece with the core Y of the engine. Y is thechannel in which the piston travels. As will be seen, the revolution ofthe piston is three hundred and fifty degrees, more or less, beinglimited in both directions by the fixed abutment Y. V is the valve,which is a double headed piston valve, reciprocating in the cylinder V Vis the entrance-port. The pressure is balanced upon the two valvepistons by the tendency of the air to expand in all directions. The endsof the valve-cylinder are perforated, and furnish exhaust-ports for theescaping air. W, V are the end-ports, communicating with the interior ofthe engine. The valvestem engages at U by a pin and slot with the leverU, so that by the one motion of the operating handle (not shown), theengineer, moving the rod U, releases the resistance cylinder 0 by thewithdrawal of the detent U releases the commutating cylinder byretracting the arm,

U and turns the air into the channel of the air-engine.

The operation of the device is as follows: The piston being at the endof its stroke the admission of air behind it can force it no farther,the left hand face of the lug Z' bearing upon the pin 1. The motion ofthe rod U being thus limited to the downward direction releases thecylinders as described, and throws thevalve V up,thus admitting the airsupplied through the pipe V and the port V to the port V and thencethrough the connecting channel V to the clearance space between thepiston and its abutment. The piston is forced around and thus rotatesthe cylinders. To rotate the engine in the opposite direction, the rod Uis thrust upward, reversing the action through the port V channel V andthe corresponding clearance space on the other side of the abutment; theroller U in this case sliding upon the inner side of the flange Z, aswill be more readily understood from Fig. 7.

The ribs Z Z &c., are cast upon the parts of the air engine to give itsufficient strength and rigidity to adapt it to the strain and shock towhich it is subjected.

The operation of thecut-out cylinder is seen in Figs. 1, 2 and 3. C isthe cut-out cylinder, to the end of which is affixed the wormgear 1actuated by the worm 1 upon the shaft 1', turned by the handle I. Uponthe gear 1 and preferably formed integral therewith, is the return-cam1, in which reciprocates the pin 1 upon the lever-arm 1. This pin may beprovided if desired with a friction roller. The lever-arm 1 is attachedto and reci procates the rock-shaft 1 Referring now to Fig. 2, it willbe seen that the shaft 1 rocks in a bearing formed in the projecting armA of the frame A. Upon the other side of this bearing the arm 1 iscarried by and rigidly keyed to the shaft 1 so that, by the rotation ofthe handle I, the cam I depresses or raises the arm 1, turns the shaft 1and correspondingly depresses or raises the arm I. Actuated by this armis the stop-block 1 a pin from which, 1 projects through the slot U inthe arm U The slot'serves as a guide for the block, sliding upon thelever arm I and the arm U takes the shock brought on the block by thestopping of the engine.

To understand the operation of the parts just described, it should bestated that the different running combinations of the motors,irrespective of the resistance, are as follows: First, all in series;second, in two groups of three; third, in three groups of two. Supposethat one of the motors be disabled by any accident, and is to be cutout, it is then desirable to still employ the mate of the disabled motorin the series positions; but it is obvious that it cannot be employed inthe multiple combinations, as it would throw the difierent circuits outof balance. I therefore provide .the cut-out cylinder with the meansjust described, which act to stop the rotation of the resistance andcommutating cylinders at the sixth position or first running position inmultiple, where the motors are divided into two groups of three each;the third position being the last one in which the mate of the disabledmotor could be used. The disabled motor and its mate would be necessaryelements in any further advance. This may be better seen from thedescription of Fig. 11, hereinafter, in which the connections andcontacts of the cylinders are shown in plane.

The rotation of the cut-out cylinder will, by the mechanism shown, shiftthe position of the stop I so that, as the cominntating cylinder isrevolved, it is brought into register with the lug Z on the flange Xaccording to the position of the cut-out cylinder; it being always inregister with the stop Z except when a motor is cut out, when itregisters with Z and the commutating cylinder is thus prevented frompassing to those positions in which either the disabled motor or itsmate are essential factors.

The sudden reversal of current in the motors while running would beproductive of serious injury, if not of immediate destruction. Thecurrent passing through the armature being assisted instead of opposedby its electro-m otive-force would burn up the motor. Although thecircuit-breaker is designed to act in the case assumed, its action mightbe too slow to prevent all damage, by reason of the inertia of itsparts, they being designed in the apparatus illustrated to break withsafety a circuit carrying two thousand seven hundred amperes at fivehundred volts potential, or about eighteenhundred electrical horsepower, and being of considerable size and weight. I therefore arrangeinterlocking devices between the commutating cylinder and the reversingcylinder in such manner that the latter is locked except when thecommutating cylinder is in its off position, with the circuit open.

The reversing cylinder has two positions. Referring to Fig. 11, where Grepresents the surface of the cylinder developed in plane, it will beseen that the two rows of contactplates are cross-connccted, so thatwhen the brushes F rest upon the upper row of plates and those marked Fupon the lower row, the current passes through the armatures in onedirection, While when the cylinder is rotated into its second position,the brushes are in the position shown in dotted lines, and the currentthen passes in the reverse sense through the armature. The two positionscorrespond to the notches G, G Fig. 1, with which the lever-arm Gengages. In this ure, a rod H is attached to and moves vertically withthe arm G having bearings in lugs H, II upon the frame A, and movingagainst the pressure of the spring H tending to depress the arm G intothe notches G, G The upper end of the rod is bent at H and engages witha pin II upon the rotary yoke C attached to the cominutating cylinder Gwhich lifts the rod and arm G The operation is as follows: So long asthe commutating cylinder is in its first position, the pin H engageswith the bent portion H of the rod II and holds the arm G from engagingwith the notches G, G The reversing cylinder is thus free to move. Whenthe commutating cylinder is moved from its illustrated position, thespring II forces down the arm G to an engagement with one or the otherof the notches G, G thus holding the reversing cylinder in place untilthe commutating cylinder is returned toits first position.

A circuit-breaker peculiarly adapted to the requirements of my improvedcontroller is illustrated in Figs. 3, 4 and 5. K is a polepiece of thearc-rupturing magnet,the yoke of which is surrounded by the coil K woundin such a direction as to force the arc upward, which in the caseillustrated, is left-handed. K, K, &c., are the sides of the chimney orbox in which the arc is formed. These parts are of some refractorymaterial, as is also the part K (shown in section in Fig. 5) which is aslab of insulation designed to protect the Winding K from any sparks ormolten metal which might drop upon it.

Turning now to Fig. 5, Q is the rod carrying the movable contacts of thecircuit-breaker; the parts illustrated in this figure showing only theshunt or subsidiary contacts. Upon the end of this rod, which should beof machinery steel,is a copper terminal or contactpiece Q, secured tothe rod by a screw, Q". In the end of this contact-piece is a smallscrew-threaded hole Q (Seen in Fig. 4.) By taking out the screw Q awirebeinginserted into the hole Q the terminal may readily be removed. Theterminals Q Q are secured to the ends of the circuit by the screws Q QTheir corresponding terminals Q, Q, are held in engagement by theleaf-springs Q Q", thus affording a ready means of renewing all of thesepieces. The entire arcing effect of the current, whenever the circuit isbroken, is localized at these contacts, as will be more fully explainedwhen the circuits are pointed out, and their ready renewal is of greatimportance.

Again recurring to Fig. 3, Q is a collar made fast to the end of the rodQ. Q is a spring, hearing at one end against this collar, and at theother against the lug T cast or otherwise formed upon the frame of theapparatus, and tending to force the rod outward, giving it a powerfulsnap-action. S is the main switch or bridging-contact between theterminals R, It, made of laminae of tempered copper or other suitablegood conducting material. lVhen forced into contact, this bridge wipesor slides over the surface of the terminals It, It, removing any dirt,and keeping them bright. This being the path of the main current, it isimperative that no injurious heating arise from imperfect contacts. Q Qare lock-nuts determining the position of the bridge S upon the rod Q.They also serve to adjust the opening of the contacts Q Q Q so that itwill occur after the bridge S has completely left the terminals R, R.

The circuits are as follows, as may be traced in the diagram shown inconnection with Fig. 11: The current entering from the trolley 70,passes around the series coil L and across the bridge S between theterminals R, R to the cable D, and so on through the controller toground. A shunt circuit is taken from the coil L around the magnet N,energizing it to attract the armature O, and thence to ground. A secondshunt circuit leaves the terminal R and passes around the blow-outmagnet K in the coil K to the circuit-making rod Q, and thence to theterminal It to rejoin the main current. This shunt is composed of ratherlarge wire, as it must be capable of carrying for an instant the entirecurrent, when the bridge S is lifted from the terminals R, R; while theshunt around the magnet N must be of small sized high-resistance wire.

T is a toggle, one arm of which is pivoted at T to the rod Q. The otherarm is a bellcrank lever having a detent T engaging with the insulatedprojection M upon the armature M, and is pivoted at T to the lug T Thetoggle is so arranged that it is never upon a dead center. T is abell-crank, also pivoted to the lug T at T, one arm of which isconnected to a rod T, going to a treadle, not shown, and the other armis arranged to engage the projection M, and by thrusting it up, torelease the detent T causing the toggle to collapse under the pressureof the spring Q, and breaking the circuit, as will be readilyunderstood. This arm also communicates the downward motion of the rod T"to the rod Q through the medium of the lug upon the back of the piece TIn any emergency, the engineer may thus, by a kick, break the circuitwithout using his hands or incurring risk.

It is important that the range of the cir- IIO cuit-breaker be limited,so that any excess or diminution of current within certain limits mayact to break the circuit automatically, and thus preserve the motorsfrom injury. Too great a current is apt to cause destruc tion of themotors, and on the contrary there is the risk that, should the currentcease for a time or fall so low that the motors slow down materially,they may be left in circuit with no resistance. As they then generate nocounter-electromotive force, when the current comes on again withstrength, as it is apt to do, it develops great torque and heats up andburns out the armatures before they can get up speed. While this is lesslikely to occur in a locomotive than with stationary motors, on accountof the constant attendance of the engineer, it is provided forautomatically as follows: I provide in the maincircuit a coil L of fewturns and large size, having a fixed iron core L, with a pole piece L.Asecond core L is arranged adjacent to this series coil, having anextension or polepiece L Between these pole-pieces is the rotary yoke 0,attached to the shaft of the commutating cylinder 0 and revolvingtherewith. The periphery of the yoke is cut-away in steps, so that theair-gaps between the pole-pieces L L and the yoke vary with the positionof the commutating cylinder, thus varying the magnetism in the core Lwhich is the active or co-operating element with the armature M. This isthe maximum coil, or coil limiting the current to a maximum beyond whichit cannot pass without disrupting the circuit.

The electro-magnet N acts as a minimum coil, and determines the lowestpoint to which the current may fall. It is provided with an armature O,hinged at O, and held down by the attraction of the core N. Attached tothe outer end of this armature is a rod P surrounded by a coil spring P,acting to raise the armature O. This rod passes loosely through thearmature M,but is provided with an enlargement or lug 1?, below it, sothat its upward motion lifts the armature out of engagement with thedetent T releasing the rod Q and breaking the circuit. To the free endof the armature M is attached the spring P, the pull of which may beadjusted by means of the lock nuts P P to oppose the spring P to anydesired degree, though it must never be so great asto prevent itspulling up the armature M when the armature O is unattracted. It will beseen from this description that when the current ceases or falls below apredetermined amount, the attraction of the core N is insufficient tohold down the armature O. The spring P then forces up the armature,carrying with it the rod P and pulling up the armature M, thus breakingthe circuit.

The function of the nuts P P is to so adjust the tension of the spring Pthat when a motor is cut out it will be increased fifty per cent. Thisis accomplished by having these nuts bear on an insulated bushing in thelever arm I, from which it is evident that when the cut-out cylinder ismoved, the spring P will be put under greater tension (adjustable to anydegree), as the upper nuts P take the normal tension of the spring P andthe lowerv nuts P may be adjusted at any desired distance from theabutting face of the insulating washer in the lever arm I. The necessityfor this additional adjustment arises from the fact that should a motorbe cut out, at the final commutation when disabled, there are two motorsin series and two in parallel which must carry in each branch (in theapparatus illustrated) thirteen hundred and fifty amperes, the normalcurrent being but about nine hundred amperes. \Vere it not for the abovearrangement to provide for this emergency, the circuit-breaker must becontinually set for an overload of fiftyper cent., which is too great amargin for safety.

The determination of the air-gap between the pole-pieces L L" and therotary yoke O is to a great extent experimental, inasmuch as themagnetic permeabilities of any two pieces of iron are unlike andunascertainable by workshop methods. Anapproximation may be had byfollowing the form illustrated; and a more accurate adjustment byaltering the balance of the springs P, P, as already explained.

As will be observed, there are three degrees of approximation betweenthe surface of the cam and the magnetic pole-pieces. This is needful byreason of the connections of the motors rendering necessary a capacityin the circuit breaker of nine hundred, eighteen hundred, or twothousand seven hundred amperes, according to the combination of themotors in series, in two branches in multiple, or in three branches inmultiple. The position of the commutating cylinder determining thecombination, and the cam 0 being fixed to the axis of this cylinder androtating with it,its position will determine the strength of themagnetic circuit and consequently the operating point of thecircuit-breaker. Thus, when the circuit is broken either by the engineeror automatically, the bridge S is lifted from the terminals R, R. Thecurrent then passes by the shunt through the .coil K energizing theblow-out magnet, and passing to the terminals Qf, &c. Upon breakingcontact at these terminals, the magnet expels the arc, and the currentceases.

In Figs. 8 and 9 I show the construction of the resistance cylinder. 0is the body of the cylinder, mounted-in suitable bearings, from which itis properly insulated. From each bearing-box projects a lug d, separatedfrom the supporting frame by insulating material d, such as soft rubber,which also acts as a cushion. Step-by-step contact plates 6, e, 850.,are arranged on the cylinder, in a manner well-known in the art, uponwhich the brushes F (Fig.10) bear to out in successive sections ofresistance in multiple as the cylinder is re- IIO volved. The auxiliarycontact c is provided for a part of these brushes, for a purposehereinafter explained; and all of the contacts are arranged over theblow-out magnetsfif, f, which prevent the destruction of the contactsurfaces by arcing, as the contacts are broken.

Fig. 10 shows the mechanical arrangement of the visible electricalconnections; the cables D, D, being those conveying the main current. h,h, &c., are the motor leads, and t',i the resistance terminal cables. F,F are the brushes of the resistance cylinder and the commutatingcylinder respectively, and F ,F are respectively one set of the brushesof the cut-out and reversing cylinders, of which brushes there are twosets upon opposite sides of the cylinders, as shown in Fig. 1, anddiagrammatically in Figs. 11, the. Between the brushes on each cylinderare septums g, 9 g of insulating material, preventing the formation ofshort-circuit-ing arcs between adjacent brushes, those on one side ofthe cut-out cylinder and on the comm utating cylinder being continuous.

Fig. 11 is a general View of the four cylinders developed in plane. Theparticular combinations shown illustrate the position of the controllerwhen the motors and resistance are connected as in the diagram 1, thebrushes of the commutating cylinder being supposed to rest on the line1-1 of the cylinder and being shown out of position to make theconnections more clear. 7

The various contact plates upon the cylinders 0 C are numberedconsecutively from 1 to 103. Several of the plates upon the cylinder 0as 45, 60, 65, 95 and 100 are cut by the development of the cylinder andare in reality continuous, the cut ends being indicated by the brokenlines at the top and bottom of the diagram. The plates are alsocross-connected, as indicated by the dotted lines. The cross-wiresconnect only the plates upon which they terminate, being insulated fromall others.

To understand the path of the current, the positions of the motors aretaken from Fig. 12, from which it will be seen that the motors areplaced in sets of two; and by tracing the circuit, that the currentpasses first into one motor of each set, and then into the others. Bythis arrangement the whole weight of the locomotive is utilized fortraction, being distributed on all the axles, and slipping of the wheelsis avoided. This particular method of connection is not essential,though useful, and may be departed from, especially in the case ofstationary motors. This method of connecction, however, gives an activeunit on each truck when cutting out three motors and changing fromseries to multiple combination; and two active units on the middle truckand one active unit on each of the end trucks, in changing from thefirst multiple to the three in multiple and two in series position.

The circuit shown in Fig.11 is as follows: The current enters from thetrolley 7t, passes through the circuit-brcaker, to the cable D, one ofthe brushes F and by the contactplate 1 upon the cylinder (J to anotherof the brushes F (although the two brushes F are metalically connectedin multiple to the cable D and serve to convey the current to thecontact plate 1, which acts as a distributing point rather than to makeconnection between the brushes,) by cable to the brush F bearing uponthe contact-plate a7 of the cylinder C". In further tracing the circuit,the brushes will not be enumerated, their office being well understood.The plate at? is cross-connected to the plate 45, from which the currentpasses to the reversing cylinder 0, passing through the motor 0 andreturning to the cylinder O at plate 52; from thence passing againthrough the reversing cylinder and through the motor 6 to plate 59 on Cby the crossconnection to the plate 56,thence to plate upon 0 thence bythe cross-connection to the plate 9 upon 0 from there passing to theresistance cylinder, all of the resistance being cut in in multiple. Atthe beginning of the motion of the resistance cylinder all theresistance is out of circuit and so long as the brushes F rest upon theplates 0 and l8,as represented, the resistance cylinder may be revolvedwithout affecting the combination of the motors and thus graduallyshort-circuit the resistance until it is cut out entirely. Returningfrom the resistance-cylinder, the current onters contact-plate 18, Cthence by cross-connection to plate 25, thence to plate 62, C bycross-connection to plate 60, through the 1110- tor a returning to plate(55, C by cross-connection to plate 66, thence to plate 29, C bycross-connection to plate 35, thence to plate 80, C back to plate 37, Cby cross-connection to plate 33, to plate 71, C by cross-connection toplate 69, through the motor ct, back to (3 to the'plate 81, through themotor Z), to (1 upon the plate 9;, by cross-connection to plate 91, to 0upon plate 10, back to O to plate 97, by cross-connection to plate 95,through the motor 0, back to C to the plate 100, by cross-connection toplate 101, thence to O on plate at, and to ground. The combination ofmotors will be asin the diagram, Fig. l, the various contacts beingomitted for clearness. From this position Fig. 3 differs only in therevolution of the resistance cylinder to a point where all theresistance is cut out. Between these two positions (which are runningpositions, as are all those marked R. R) there are nine others,according to the amount of resistance in circuit, determinedbythepositionofthecylinderO. There are therefore ten speeds with all themotors in series, corresponding to the detent notches in the cylinder 0,Fig. 2. By tracing the circuits with the brushes F on the line 2-2, C itwill be seen that the resistance terminals are also short circuited uponthe commutating cylinder.

The nine notches close to- IIC

